Screen printing a photographic image on a T-shirt with halftones
Putting a photograph onto a tee isn't the mystery many people imagine. Screen printing can reproduce gradient, shadow, and fine photographic detail — it just needs the image broken into dots first, then the right screen, emulsion, and ink for the garment in front of you.
The technique is called halftone. Continuous tone becomes a pattern of dots of varying sizes. The eye blends those dots into smooth-looking gradients from a distance away, which is why halftone has been the standard in magazines and posters since the 1800s — and why it works just as well on a heather navy tee at the markets in Fitzroy.
A solid halftone job starts well before the screen touches the platen. Files must be separated, screens exposed properly, and inks suited to the shirt colour. Skimp on any step and the print turns muddy, choppy, or washed out.
The payoff is real. Photographic tees sell at weekend markets, look sharp as staff uniforms, and make classic keepsakes for events from the Gold Coast down to Hobart.
What a halftone actually does
A halftone replaces continuous tone with a dot pattern. Smaller, tightly packed dots read as shadows; larger, spaced-out dots read as highlights. The closer the dots, the darker the area appears.
A single-colour halftone reduces a black-and-white photo to dots of one ink, and is often the quickest way for real estate agent promotional products to carry a recognisable image of a property or sale sign. A four-colour process (CMYK) job uses four screens, each carrying a halftone of one colour that overlaps on the shirt to mimic full-colour photography. Spot colour works the same way — a vintage surf photo printed in one rust or teal still relies on halftone dots to look photographic.
The two numbers that matter are LPI (lines per inch) and dot shape. LPI sets how fine the pattern reads. Dot shape — round, elliptical, or square — affects how the print feels, how it ages, and how forgiving it is on rougher fabric.
Mesh, emulsion, and line screen
| Mesh Count | Halftone LPI Range | Best For |
|---|---|---|
| 110 | 30–40 LPI | Bold graphics and heavy tees |
| 156 | 45–55 LPI | General photographic work |
| 200 | 55–65 LPI | Portraits and finer gradients |
| 305 | 70–85 LPI | Detailed photos on white shirts |
Higher mesh counts lay thinner ink deposits and reproduce finer dots, but they struggle on textured or pigment-dyed garments. For most photographic jobs on mid-weight cotton, a 156 or 200 mesh screen with a 55 LPI halftone is the dependable choice. Lower mesh counts stay forgiving and bold, which suits nostalgic single-colour photos on chunky ringspun tees.
Preparing the artwork
Start with a high-resolution image — at least 300 dpi at the actual print size. Photos shot in good, even light, like a wedding in the Barossa or a market shoot on the Mornington Peninsula, will separate far better than contrasty, underexposed files.
Convert the image to greyscale (for one-colour prints) or CMYK (for four-colour jobs), then run it through a halftone filter in Photoshop or Affinity Photo. Most apparel shops use elliptical dots at 45 degrees, which gives smoother transitions and less moiré on fabric. Stick to one angle where possible.
When separating CMYK, work each colour channel on its own. Black carries the detail, cyan and magenta carry the colour, and yellow softens skin tones. Always print a laser proof at actual size before burning screens — a quick proof saves a long arvo at the press.
Exposure and stencil quality
Halftones need a fully cured stencil that holds every dot cleanly. Soft, washed-out, or chipped edges look muddy at the press and the dots break up under the squeegee.
Check the film's Dmax — anything below 4.0 won't fully block UV. Exposure times vary by emulsion thickness, light source, and humidity, so test strips aren't optional. A 156 mesh coated with standard dual-cure emulsion typically wants six to nine seconds under a metal-halide unit, but every shop runs differently.
Wash out gently with a soft spray. Halftone dots at 55 LPI and above are tiny; a stiff brush tears them off the mesh. Dry the screen flat, out of direct sun.
Inks and underbase
White underbase is non-negotiable for photographic prints on coloured tees. Flash-cure the white first, then print the halftone colours on top while the underbase is still tacky. The underbase gives the inks something to sit on, stops cotton dulling the colour, and keeps the dots from sinking between fibres.
For a single-colour job — say, a black-and-white image in metallic gold on charcoal — the underbase can be skipped if the shirt isn't too dark. Plastisol is the workhorse of Australian garment printers because it sits on top of the fabric, holds detail well, and cures predictably at 160°C.
Water-based inks give a softer hand and an old-school feel for smaller runs, and they take well to heavier fabrics like the cotton duck used for custom catering aprons, where the underbase is often left off entirely. They're a touch fussier on press, though — Brisbane summer humidity will change how the ink lays down, so dial in pressure a little lighter than you would in winter.
The press run
Off-contact matters. Halftone dots are unforgiving — too much pressure flattens them, too little and the print looks thin. Set off-contact at roughly 1.5 to 2 mm for a 156 mesh screen, slightly higher for finer meshes.
Flood the screen well before each print, then push a single, even stroke. Multiple passes mush the dots together and the gradient stops looking photographic. Use a sharp 70 durometer squeegee for the underbase and a softer 60 durometer blade for the halftone layer. Run a couple of test tees at the start of each run to dial in pressure.
Let the underbase flash off properly before laying colour. If a clean thumbprint pressed into the flashed white doesn't transfer to your skin, you're set.
Troubleshooting
Moiré between the mesh and halftone usually means a bad angle. Rotate the halftone 7 degrees off 45 and try again. If the pattern persists, rotate the artwork, not the screen.
Uneven dots point to uneven pressure or a worn squeegee. Check the blade with a loupe — if it's dull, swap it. Dots that disappear often mean an underexposed screen or over-aggressive washout. Dots that bleed together usually mean too much pressure, too soft a squeegee, or off-contact set too tight.
If a print passes every check at the press but looks washed after the first cold-water wash, the cure temperature is the usual suspect. Run a dryer test strip before the main run.
Photographic halftones reward preparation and patience. Pick the right mesh, separate the artwork carefully, expose a clean stencil, and the rest is steady, repeatable press work. Once the basics are dialled in, the same technique carries across other decorated items too. For brands pushing past apparel, promotional drinkware holds photographic detail cleanly on ceramic and stainless blanks, and the same workflow translates without much fuss. The team at LOCK Promo can walk through mesh counts, separations, and ink choices for the next photographic print run — reach out today to talk through your setup and book the job in.